1. Technical Field of the Invention
The present invention relates to a vertical type of double disc surface grinding machine which simultaneously grinds upper and lower end surfaces of a work like a brake disc of a vehicle held by a work holding jig by means of a pair of upper and lower grinding wheels. More particularly, it relates to an improvement in a clamp device for said grinding machine which grinds the work rotated by the work holding jig.
2. Prior Art
Conventionally, the clamp device for clamping the work to the self rotatable work holding jig has been equipped with a clamp metal such as a clamp claw or a clamp arm in a manner as vertically movable, so that the work has been secured to a specified position of the work holding jig by pushing the clamp metal from upside against a proper position of a work upper surface.
Especially, respect to a work which is a rotating body such as a disc brake for automobile and which has a wide ground surface and provided with a specified rigidity so as no to be deflected even when it is held at its center; a center position of the work is clamped to the work holding jig and the work is self rotated together with the work holding jig so that an outer peripheral portion of the work is inserted in between the grinding wheels.